The big awful truth about biodegradable plastics
Contrary to what their name suggests, a comprehensive new UN report on marine plastics confirms that most plastics labeled as biodegradable don't break down in the ocean.
We’ve all seen the photos; the grim images of marine animals tangled up and tortured in the plastic chaos of our detritus. Some estimates put plastic pollution as the cause of death for 100 million marine animals every year, while a study from Imperial College London last year concluded that plastic will be found in 99 percent of seabirds by 2050.
Plastic is one of mankind’s more confounding inventions; while its innovations have ushered in convenience and advances like few other materials, it’s very nature is rife with contradiction. It’s remarkably durable; it’s cheap and easy to manufacture, making it the first choice for single-use items. Thus we have an incredibly enduring material that is often used just once before being thrown away.
So with visions of plastic-wrapped sea lions lodged in our heads, many of us reduce our plastic and opt for biodegradable plastic whenever we can. We think that something marketed as biodegradable will actually biodegrade. Alas, we think wrong according to scientists. Last year, the United Nations Environment Programme (UNEP) published a report on biodegradable plastics revealing that they rarely actually degrade. As TreeHugger noted when we wrote about the report: "biodegradable plastcs require long-term exposure to high-temperatures (around 122F, or 50C), like those found in large municipal composters, to actually break down. Those conditions are not found very often in nature, and especially not in the oceans.”
And now the same UN agency has published a new report, "Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change," which reiterates the previous findings.
Right there on page xi of the Executive Summary: “Plastics marked as ‘biodegradable’ do not degrade rapidly in the ocean.”
As Jacqueline McGlade, chief scientist at the UN Environment Programme, explains to the Guardian:
It’s well-intentioned but wrong. A lot of plastics labelled biodegradable, like shopping bags, will only break down in temperatures of 50C [122F] and that is not the ocean. They are also not buoyant, so they’re going to sink, so they’re not going to be exposed to UV and break down.
And adding to the abysmal miasma is that some of the additives that help make biodegradable plastics break down make it harder to recycle, and are potentially harmful to the natural environment.
“There is a moral argument that we should not allow the ocean to become further polluted with plastic waste, and that marine littering should be considered a ‘common concern of humankind’,” the authors of the report conclude.
“Warnings of what was happening were reported in the scientific literature in the early 1970s, with little reaction from much of the scientific community.”
Four decades later, the time might be now or never.
Via Huffington Post